The US Federal Maritime Commission (FMC) has launched a new investigation into whether ocean common carriers are restricting truckers and shippers from choosing their own chassis providers — a move that could shake up how container boxes move off vessels at US ports.

In a notice published Monday, the FMC said it’s looking into practices that may “unjustly or unreasonably restrict” motor carriers’ and shippers’ ability to negotiate with and select chassis providers of their choice. The agency is calling for input from shippers, truckers, logistics providers and the broader public on any restrictions tied to carriers’ association rules, service contracts or terminal arrangements that steer chassis business away from open competition. Public comments are due by March 27, 2026.

The probe is rooted in past commission rulings. In February 2024, the FMC found that rules used by some ocean common carriers to lock in exclusive chassis providers in four key US markets violated the Shipping Act, and ordered those practices to stop. Ongoing reports that carriers have continued to enforce those kinds of restrictions prompted the new investigation to see if the cease-and-desist orders are being followed.

The chassis fight has been simmering for years. Shippers and truckers have long argued that limited choice and carrier-linked equipment management groups have kept chassis rates high and competition low. Freight industry sources say the lack of genuine choice can ripple into port dwell times, driver costs and fleet efficiency — issues that carriers and terminals have struggled to manage since the pandemic.

This latest action fits into a broader uptick in FMC enforcement and oversight.

In early January 2026, the FMC slapped a major container shipping and logistics provider with a precedential order totaling over $22m in civil penalties, making clear that repeated billing errors and tariff inaccuracies can be unlawful practices under the Shipping Act.

In late 2025, the agency collected about $1.35m in penalty payments from a vessel-operating carrier and an NVOCC for Shipping Act violations tied to tariff publication and service rule breaches. Earlier in 2025, the FMC opened an investigation into whether some foreign port policies — especially moves in Spain that limited US-flagged vessels’ access — create “unfavorable conditions” for US foreign commerce and could warrant fines or other remedies. In mid-2025, the commission also took up a broader inquiry into flagging practices, including concerns about how “flags of convenience” might affect operating standards, competition and safety across global trades.

Regulated parties say these probes and enforcement actions signal a more assertive FMC ready to press carriers on competitive practices well beyond basic rate issues. Critics of carrier conduct argue that decades of consolidation have left shipping lines with outsized influence over equipment pools, service contracts and supply chain touchpoints — and regulators are now trying to claw back more open conditions for freight owners and haulers.

Whatever the outcome of the chassis probe, carriers and ports will be watching closely. If the FMC determines that restrictions remain in place despite earlier orders, it could lead to enforcement actions, civil penalties or new compliance requirements for carriers doing business under the US Shipping Act.